These points are also on the negative side of the x axis, at -pi/4 and -pi/2. When we move along the x axis, notice what happens to the y value. On the left side of zero, tangent is negative. At x=-pi/4, tangent=-1.
The Independent Online. David Cameron may have called a referendum on the EU to blackmail Europe, according to Vladimir Putin. The Russian president also questioned Mr Cameronâs decision to call the vote, as it has caused a âgreat problemâ.
1 of 25. Russian President Vladimir Putin carries a hunting rifle on Aug. 15, 2007, in the Republic of Tuva. Putin has been no stranger to the former Soviet Union's limelight, having held top positions in the country for more than 25 years. Dmitry Astakhov/AFP/Getty Images. 2 of 25. Then-Russian Prime Minister Vladimir Putin swims the butterfly during his vacation outside the town of Kyzyl on Aug. 3, 2009, in southern Siberia.